Door security device

ABSTRACT

A door-locking device includes a chain which is anchored to a plate which is in turn screwed to the inside edge surface of the door frame jamb. A stud on the free end of the chain can be inserted into a slot in a door-plate screwed on the inside face of the door to provide a chain guard. An arm hinged on the outer end of the first plate can swing so that it abuts the door completely preventing it from opening. Aligned slots in the door plate and the arm receive the stud so as to lock the arm in its locking position.

Saunders Oct. 2, 1973 1 DOOR SECURITY DEVICE [76] Inventor: David Frederic Saunders, 166

Cowan Ave, Toronto, Ontario, Canada [22] Filed: Aug. 23, 1971 [21] Appl. No.: 173,743

Bowling 292/264 Gewerty et al. 292/264 Primary Examiner-Richard E. Moore Att0rney.l. Noel Walton [57] ABSTRACT A door-locking device includes a chain which is anchored to a plate which is in turn screwed to the inside edge surface of the door frame jamb. A stud on the free end of the chain can be inserted into a slot in a doorplate screwed on the inside face of the doorto provide a chain guard. An arm hinged on the outer end of the first plate can swing so that it abuts the door completely preventing it from opening. Aligned slots in the door plate and the arm receive the stud so as to lock the arm in its locking position.

28 Claims, 9 Drawing Figures PATENTEU m 3.762.752

SHEET 30F 4 PATENTEDBBT 2 m 3.752.752

SHEET t 0F 4 A 17 I 1 I75 700 7% 140 I 20 DOOR SECURITY DEVICE BACKGROUND OF THE INVENTION The present invention relates to locking devices and more particularly to locking devices for use on doors. The locking devices to which this invention relates are of the type which include a length of chain to allow a door to be opened partially so that a householder can then ascertain the identity of a visitor before opening the door completely to permit entry.

The simplest form of chain lock or chain guard as presently commercially available comprises a length of chain having one end anchored to a mounting plate which is secured to the jamb of the door frame, the opposite end of the chain being secured to a stud which is slidably received in a slotted slide plate which is secured to the inner face of the door. When it is desired to open a door on which such a known chain guard is fitted, the door is first closed and the stud is then slid along the slot in the door plate to an enlarged opening at one end of that slot and through which the stud can then be withdrawn.

Chain guards in which one end of the chain is releasably anchored by a key-operated lock are also known but this type of guard is consequently more expensive to manufacture.

An important practical disadvantage of the presently commercially available chain guards is that their effectiveness in use depends almost solely on the strength of a length of chain.

It is accordingly an object of this invention to provide a locking device which presents many of the advantages of known chain guards while permitting an improved positive locking of a door in its fully closed position without such locking being dependent on the strength of a length of, chain.

Another object of this invention is to provide a locking device of the chain guard type and which device additionally comprises means fo locking a door in its fully closed position.

Yet another object of this invention is to provide a locking device of the aforesaid type and which does not require the provision of a key-operated locking means for locking the door in its fully closed position.

A further objectof this invention is to provide a locking device of the aforementioned type and which device has an exceedingly simple construction and consequently a very low manufacturing cost.

Another object of this invention is to provide a locking device which is easily mounted for use and which can accommodate variations in the spacing between a door and the jamb of the door frame in which that door is hung.

Yet a further object of this invention is to provide a locking device which cannot accidentally be moved easily into its locking position.

Other objects of the invention will become apparent as the description herein proceeds.

SUMMARY OF THE INVENTION The present invention provides a locking device for use on a door having inner and outer faces and a free edge and which door is hingedly mounted at its opposite edge in a door frame including a jamb having an edge surface which is opposite the free edge of the door when the door is in its fully closed position.

More particularly, a locking device in accordance with this invention is operative in a first locking position thereof to secure a door in a fully closed position thereof, to allow partial opening of the door when the device is in a second locking position thereof and to allow the door to be opened completely when the device is in 3 released position thereof.

Broadly, a locking device in accordance with this invention comprises a first mounting member adapted for attachment to the door; a second mounting member adapted for attachment to the jamb of the door frame; a chain permanently secured to a first one of the first and second mounting members and releasably attached to a second one of those first and second mounting members and of such a length to allow only partial opening of the door when it is attached to the second one of the first and second mounting members; a locking member movably mounted on one of the first and second mounting members for movement of that member between a locking position in which it is effective to hold the door in a fully closed position and a released position in which the door can be opened; and a holding member operatively associated with the locking member for releasably holding that locking member in its locking position.

In a particularly preferred embodiment of a locking device in accordance with this invention, the locking member of such a device is in the form of an arm which in hingedly mounted on the second mounting member for pivotal movement between a first position in which the door can be opened and a second or locking position in which the arm effectively abuts the inner face of the door to prevent opening of the door from its fully closed position.

In accordance with another particularly preferred feature of this invention and in a device of the specific type hereinbefore described, the holding member which functions to hold the arm in its locking position is constituted by a stud to which one end of the chain of the device is connected. Such a stud can be inserted for free sliding movement into a slotted door plate forming the aforementioned first mounting member, the slot being dimensioned at a first end thereof to allow removal of the stud from the slot only when the door is essentially in its closed position.

In such a specific structure for a locking device in accordance with this invention, the aforementioned arm is adapted releasably to be engaged by the stud when that stud is moved toward a second end of the elongated slot in the door plate thereby to maintain that arm in the aforementioned second or locking position thereof.

Other preferred features for such a particular embodiment of a locking device in accordance with this invention will be explained in more detail as the description herein proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described merely by way of illustration with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of one embdoiment of a locking device in accordance with the present invention and showing a chain forming part of that device fragmentarily as well as showing the device mounted on a door and in its unlocked or released position;

FIG. 2 is a horizontal sectional view through FIG. 1 when taken as indicated by the arrows 22 of that figure and showing the locking device in its first locking position, in which position it is effective positively to secure the door on which it is mounted in a fully closed position thereof, the chain being shown fragmentarily;

FIG. 3 is a horizontal sectional view similar to that of FIG. 2 but showing the locking device in its second locking psoition in which position it is effective to allow partial opening of the door, the stud of the device also being shown in phantom outline in an inoperative position thereof;

FIG. 4 is an enlarged axial sectional view through a stud of the device when taken as indicated by the arrows 4-4 of FIG. 1;

FIG. 5 is a vertical sectional view through FIG. 1 when taken as indicated by the arrows 5-5 of that figure and showing the stud disposed in the slotted door plate, the chain again being shown fragmentarily;

FIG. 6 is a perspective view of an alternative embodiment of a locking device in accordance with the present invention, the chain of the device being shown fragmentarily;

FIG. 7 is a perspective view of yet another embodiment of a locking device in accordance with this invention and showing the device in its first locking position;

FIG. 8 is a perspective view of the locking device of FIG. 7 showing that device in its released or unlocked position; and

FIG. 9 is a fragmentary perspective view of an alternative construction for one component of the locking device shown in FIGS. 7 and 8.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The locking device generally indicated at 10 in FIGS. 1 to 3 of the accompanying drawings is shown in those figures as being used on a door which is generally indicated at 12 and which has an inner face 13, an outer face 14 and a free edge 15. The door 12 is hingedly mounted in a door frame including an upright jamb 16 which has an edge surface 17 which in opposite the free edge'lS of the door 12 when that door is fully closed as shown in FIGS. 1 and 2. The jamb 16 is anchored to a wall 18 in any known manner and, as is conventional, an abutment or stop moulding 19 is secured to the jamb 16, for example, by nailing, so as to abut the outer face 14 of the door 12 when the latter is closed. A curved moulding strip or casing 20 is shown as being mounted on the outer face 21 of the jamb 16 as is conventional. V The locking device 10 includes a first mounting member or door plate generally indicated at 23 and which is secured to the door 12 on its inner face 13 by screws 24. The door plate 23 is generally rectangular and is formed along three sides with edge flanges 26 in which openings are provided at each of the four cornets of the plate for receiving the mounting screws 24. It will be seen that the door plate 23 is mounted on the inner face 13 of the door 12 so that its right-hand edge 28 is disposed essentially along the corner of the door between the inner face 13 and the free edge 15 of that door. 7

Between the edge flanges 26 the door plate 23 is formed with a forwardly disposed front wall 31 and with side walls 32, 33 and 34 which together define an elongated compartment 38. Although the mounting plate 23 of the device 10 is shown as being in the form of a unitary metal stamping, it should be understood that it is equally within the scope of this invention to construct the plate in other ways, for example, by casting or extrusion, or by assembly from a number of separate components.

Referring further to the door plate 23, it will be seen that the front wall 31 of that plate is formed with an elongated slot generally indicated at 40 therein. At its first or left-hand end, the slot 40 is widened in the vertical direction to provide an enlarged opening generally indicated at 41. At the second or right-hand end of the slot 40, there is provided a second enlarged opening generally indicated at 42 and which opening extends downwardly from the slot 40. For a reason which will be more readily understood as the description herein proceeds, the opening 42 has a width less than the width of the opening 41.

The locking device 10 also includes a second mounting member generally indicated at 43 and which is in the form of an elongated plate 44 having holes therethrough to allow that plate to be screwed to the edge surface 17 of the jamb 16 by means of screws 45. When so secured to the jamb 16, the plate 44 extends beyond the surface 21 of the jamb 16 to a hinge sleeve generally indicated at 46. In accordance with another feature of this invention, the plate 44 can be bent slightly as I shown at 47 so as to ensure that the door 12 is not prevented from opening by the hinge sleeve 46. The extent to which the plate 44 is bent is shown somewhat exaggerated in FIGS. 1 to 5 of the accompanying drawings. In the particular device 10, the plate 44 terminates in two tongues 48 and 49 which are formed into spaced apart and aligned sockets for a hinge pin 50.

The locking device 10 also comprises a locking member or arm generally indicated at 52 which comprises an elongated plate 53 terminating in a tongue 54 which is formed to provide the central socket of the hinge sleeve 46. The plate 53 includes a first portion 56 which is bent to conform to the corresponding portion of the elongated plate 44 when the arm 52 is disposed in its locking position as shown in FIGS. 1 and 2. A-second portion 57 of the plate 53 extends generally perpendicularly to the first portion 56 thereof and terminates in an outwardly projecting handle portion 58 which is appropriately shaped as desired.

It will be noted that the second portion 57 of the plate 53 is formed with a slot 60 which extends downwardly into the plate 53 from the top edge 61 of that portion 57 of the plate 53. It will be further noted, particularly by reference to FIG. 1, that the slot 60 is aligned with the aforementioned opening 42 in the front wall 31 of the door plate 23 when the arm 52 is moved into its closed or locking position as illustrated in FIGS. 1 and 2 but that the slot 60 has a smaller width than does the opening 42. For a reason which will be more readily understood as the description herein proceeds, the top edge 61 0f the second portion 57 of the plate 53 is disposed some distance below the slot 40 in the front wall 31 of the door plate 23. In accordance 20 as will be readily understood by reference to FIGS. 2 and 3.

At the opposite end of the chain 64, a terminal link 68 thereof is secured to a stud generally indicated at 69 and which is shown in greater detail in FIG. 4. The stud 69 comprises a rear guide plate 70 which is integrally formed with a shaft generally indicated at 71 and having a large diameter portion 72 extending forwardly from the guide plate 70 and a smaller diameter front portion 73. A forwardly facing and radially extending shoulder 74 is formed between the two shaft portions 72 and 73. The rear guide plate 70 has a generally rectangular configuration and is dimensioned so that it can be inserted into the compartment 38 of the door plate 23 through the enlarged opening 41 in the front wall 31 of that door plate. The dimensions of the rear guide plate 70 are, however, larger than those of the enlarged opening 42 so that the plate 70 cannot pass through the opening 42 whatever the position of the shaft 71 in that opening. The diameter of the rear portion 72 of the shaft 71 is smaller than the vertical width of the slot 40 but larger than the width of the neck 62 of the slot 60 while the diameter of the front portion 73 of the shaft 71 is slightly smaller than the width of that neck 62.

At its forward end, the shaft 71 is riveted as at 76 to a front guide plate 77. A washer 78 is disposed around the front portion 73 of the shaft 71 and a helical compression spring 80 also disposed around the front portion 73 between the washer 78 and the front guide plate 77 is effective to urge the washer 78 normally into abutment with the shoulder 74. The terminal link 68 of the chain 64 is disposed about the front portion 73 of the shaft 71 radially outwardly of the spring 80.

Having described the construction of the locking device shown in FIGS. 1 to 5 of the accompanying drawings, the manner in which that device functions will now be summarized. With the door plate 23 secured to the inner face 13 of the door 12 by the screws 24 with the slot 40 disposed generally horizontally as shown and with the elongated plate 44 mounted on the edge surface 17 of the jamb 16 by the screws 45, the rear guide plate 70 of the stud 69 can be inserted through the opening 41 in the front wall 31 of the door plate 23 when the door is closed. The stud 69 can then be slid along the slot 40 toward the right-hand end thereof. In this way, the locking device 10 functions essentially as a conventional chain guard allowing partial opening of the door 12 as shown in FIG. 3, the chain 64 having such a length that the door 12 must be essentially completely closed before the stud 69 can be withdrawn through the opening 41. If the arm 52 is first swung into the position shown in FIGS. 1 and 2 and the stud 69 is then first moved along the slot 40 and then downwardly into the slot 60 in the arm 52 by pressing on the front guide plate 77 to displace the shaft 71 rearwardly so that the shaft 71 of that stud 69 extends through both the opening 42 as well as through the slot 60, the stud 69 is then effective to prevent movement of the arm 52 out ot its locking position and so completely prevents opening of the door 12. It will be understood that the stud 69 functions as a holding memher which is operative to maintain the locking member constituted by the arm 52 in its locking position. Accidental upward displacement of the stud 69 from the slot 60 is impossible since the front guide plate 77 must first be moved rearwardly against the action of the spring 80 before the stud 69 can be moved through the neck 62 of that slot. It will now be understood that the neck 62 of the slot 60 and the described structure of the stud 69 together constitute a detent means for preventing accidental release of the stud 69.

By removing the stud 69 from the slot 60 in the manner described, the door 12 can be partially opened by moving the arm 52 to the position shown in FIG. 3 with the chain 64 still connected to the door by engagement of the rear guide plate of the stud 69 with the front wall 31 of the door plate 23. When it is desired to open the door 12 completely, the stud 69 is moved along the slot 40 with the door essentially fully closed until the rear guide plate 70 of the stud 69 can be withdrawn forwardly through the opening 41. When removed from the slot 40, the stud 69 can be placed for convenience in the slot 60 in the arm 52 as indicated in phantom outline at 69' in FIG. 3.

The alternative embodiment of a locking device as generally indicated at 82 in FIG. 6 of the accompanying drawings has many features in common with the locking device 10 already described herein and, to avoid undue duplication of the description, identical components of the two devices are indicated by the same legends. The device 82 differs from the device 10 in that it includes a door plate generally indicated at 83 which is usefully formed as an extrusion. The door plate 83 is intended to be mounted on the inner face 13 of the door 12 by screws 24.

The locking device 82 includes a locking member or arm generally indicated at 84 which is similar to the arm 52 of the device 10. The arm 84 differs from the arm 52, however, in that a downwardly extending slot 85 formed therein is not provided with a narrower neck corresponding to the neck 62 of the slot 60 in the arm 52 of the device 10, the stud 86 of the device 82 being retained in the slot 85 solely by gravity.

It will also be seen from FIG. 6 that the door plate 83 has an elongated slot 87 formed in a front wall 88 of that plate and that the plate 83 is secured to the inner face 13 of the door 12 so that the slot 87 is disposed generally vertically thereon. At its upper end, the slot 87 is widened to provide an enlarged opening indicated at 89. It will also be noted that the slot 85 in the arm 84 is slightly wider than the slot 87 for the purpose of accommodating variations in the spacing between the free edge 15 of the door 12 and the opposed inner edge surface 17 of the jamb.

The stud 86 is shown in FIG. 6 as being formed as a length of extruded metal including rear flanges 90 and 91 and front flanges 92 and 93, the front and rear flanges being separated by a relatively thick web 94. which also extends forwardly of the front flanges 92 and 93 as indicated at 95 and to which one end of the chain 64 is pivotally connected by a shackle 96. The opposite end of the chain 64 is anchored through a hole 97 formed in the lower end of the hinge pin 98 of the hinge 46. I

It should also be noted that the enlarged opening 89 in the door plate 83 is large enough to allow the rear flanges 91 and 92 on the stud 86 to be inserted into the door plate 83 so that they are then disposed behind the edges of the front wall 88 as the stud 86 is moved along the slot 87. With the arm 84 in the locking position illustrated in FIG. 6, the stud 86 can be slid downwardly along the slot 87 after insertion through the opening 89 7 until the front flanges 93 and 94 of that stud 86 engage the arm 84 on respective sides of the slot 85 therein thereby effectively locking that arm in the position illustrated. It should be understood that the flanges 93 and 94 are large enough to extend beyond respective side edges of the slot 85 at all relative horizontal posifirst closed, and the stud 86 is moved upwardly along the slot 85 and withdrawn through the opening 89. The length of the chain 64 and the length of the slot 87 in the door plate 83 will normally be such that the stud 86 cannot be removed through the opening 89 unless the door is essentially fully closed.

The further embodiment ofa locking device in accordance with this invention and as generally indicated at 100 in FIGS. 7 and 8 of the accompanying drawings has many features in common with the locking devices and 82 already described and identical components of the several devices are indicated by the same legends.

The device 100 includes a door plate generally indicated at 101 which is formed with edge flanges 102 having holes formed therein to receive screws 24 by means of which that door plate 101 can be secured to the inner face 13 of the door 12. An elongated slot 103 is formed in a front wall 104 of the door plate 101, the slot 103 being disposed generally horizontally when the plate 101 is so mounted on a door. At its lefthand end, the slot 103 is provided with an enlarged opening 106 so that a rear plate 135 of a stud generally indicated at 132 of the device 100 can be inserted into the slot 103 for movement therealong in a conventional manner.

It is usefully to be. noted at this juncture that the door plate 101 includes side walls 112 which are somewhat deeper from front to back than the walls 32, 33 and 34 of the device 10 and the corresponding walls of the device 82 already described herein.

The locking device 100 also comprises a mounting plate generally indicated at 116 which is secured to the edge surface 17 of the jamb of a door frame in the same way as the plate 44 of the device 10 was secured to such a jamb edge surface. At its outer end, the plate 116 is provided with a tongue which is bent to form a central hinge sleeve section 117.

A further component of the locking device 100 is a trapezoidal arm generally indicated at 120 which is integrally formed with upper and lower hinge sleeve sections 121 and 122 respectively. A hing pin shown in phantom outline at 123 extends through the hinge sleeves I21, 117 and 122 for pivotal mounting of the arm, 120 on the mounting plate 116 for movement of that arm 120 between the positions shown in FIGS. 7

and 8. I

A slot 126 is formed in the arm I and extends gencrally horizontally intothat arm from the free outer end 127 thereof so that, when the arm is disposed in its locking position as shown in FIG. 7, the slot 126 is aligned with the elongated slot 103 in the door'plate 101 as will readily be understood by reference to FIG. 7.

The device 100 also includesa chain generally indicated at 130, one end of which is permanently anchored to an eye 131 integrally formed with the hinge pin 123 at the lowe end thereof. The stud generally indicated at 132 is secured to the other end of the chain 130. The stud 132 includes a shaft 133 to which spaced apart and generally circular front and rear plate 134 and 135 respectively are suitably secured, the rear plate 135 being dimensioned so that it can be inserted through the aforementioned opening 106 for free sliding movement along the slot 103 with the rear plate 135 engaging the rear surface of the front wall 104 of the door plate 101. The separation between the front and rear plates 134 and 135 respectively of the stud 132 is such that the latter can be slid into the slot 126 in the arm when the latter is pivoted to its closed or locking position as shown in FIG. 7 with that arm 120 abutting the front surface of the front wall 104 of the door plate 101. I

By forming the arm 120 with the generally trapezoidal configuration illustrated, that arm 120 extends upwardly and downwardly beyond the front wall 104 of the door plate 101 so that the arm 120 can easily be held for moving it out of its locking position.

As a result of forming the door plate 101 with relatively deep walls 112, the arm 120 can be formed as a generally planar member without danger of that arm being prevented fromopening completely by its engagement with the casing 20 on the door frame.

It will also be seen that the hinge pin 123 of the device 100 is formed at its upper end with an upward extension 140 of such a diameter that a link of the chain can be placed thereover as actually shown in FIG. 7 for the purpose of preventing accidental displacement of the stud 132 out of the slot 126 in the arm 120 when the latter is disposed in its locking position. It will now be understood that the upward extension of the hinge pin 123 provides a chain-anchoring member which functions as a detent means for preventing accidental unlocking of the stud 132 from the arm 120.

In the particular locking device 100 shown in FIGS. 7 and 8, the hinge pin 123 is removably retained in the hinge sleeve sections 117, 121 and 122 by a spring washer 142 disposed in an annular groove in the hinge pin extension 140, a simple washer 143 usefully also be provided below the hinge sleeve section 122. Such optional provision of a removable hinge pin is advantageous in that it permits simple reversal of the hinge pin in the event that the locking device 100 is to be used on a door which is hinged along its right-hand vertical edge instead of on the door 12 which is illustrated as being hinged along its left-hand vertical edge. It should, however, be understood that, for the particular embodiment of a locking device in accordance with this invention as indicated at 100 in FIGS. 7 and 8, it is equally possible removably to retain the hinge pin 123 in the hinge sleeve sections 117, 121 and 122 by means other than the spring washer 142. For example, a set screw can be provided in one of those hinge sleeve sections for such a purpose.

It is also possible to modify the construction of the 1 locking device 100 of FIGS. 7 and 8 in a different manner so as to avoid the need for providing a removable hinge pin while still allowing the device to be used on doors hinged along their left-hand vertical edges as well as on doors hinged along their right-hand vertical edges.

One such further modification is shown in FIG. 9 in which there is illustrated generally at 146 a hinge including two essentially identical leaves 147 and 148 and a hinge sleeve generally indicated at 149. The leaves 147 and 148 are formed with open-ended slots 150 and 151 respectively therein and with four screw mounting holes 152 by means of which a selected one of the leaves 147 and 148 can be secured by screws 153 to the edge surface 154 of the jamb of a door frame.

The hinge 146 also includes a non-removable hinge pin which is formed at one end thereof with a collar 156 and with an extension 157 which serves as a chainanchoring means in the same way as does the extension 140 of the hinge pin 123 of the device 100 of FIGS. 7 and 8.

At its opposite end, the hinge pin of the hinge 146 is formed with a second extension 160 having an opening 161 therethrough to allow the chain 130 to be anchored thereto.

For use on a door which is hinged along its righthand vertical edge (viewed from the inside), the leaf 148 is screwed to the jamb as actually shown in FIG. 9 and accordingly that leaf 148 then corresponds to the mounting plate 116 of the device 100 of FIGS. 7 and 8. For use on a door hinged along its opposite vertical edge, the other leaf of the hinge 146, namely the leaf 147 thereof, is secured to the jamb of the door frame and the leaf 148 then constitutes the arm corresponding to the arm 120 of the device 100. lt will now be understood, that with this particular construction, it is not necessary to invert the hinge 146 for use on a door which is hinged along its opposite edge. Consequently, the hinge pin can be permanently secured in the hinge sleeve.

It will now be understood that the present invention provides a highly effective locking device which has an extremely simple construction. The devices 10, 82 and 100 as shown in the accompanying drawings also present several other practical advantages. For example, by forming the slot 60 in the arm 52 of the device 10 so that it has a different width than the opening 42 in the front wall 31 of the door plate 23 as shown, variations in the spacing between the free edge of the door 12 and the edge surface 17 of the jamb 16 can be accommodated without preventing operation of the locking device. Such a feature is also provided in the device 82. It will, however, be understood that it is equally within the scope of this invention alternatively to provide the opening 42 of the device 10 with a relatively narrow width and the slot 60 in the arm 52 of that device with a greater width. This is of course unneccessary in the device 100 shown in FIGS. 7 and 8 since the relative horizontal positions of the arm 120 and the door plate 101 of that device will not affect its operation.

Another important advantage of the locking devices 10, 82 and 100 is that their mounting on a door does not require extreme accuracy, some variation in the relative positions of the components secured to the door and the jamb of the door frame being possible. In

. the case of the device 100, it will be desirable to form the stud 132 with a shaft 133 of a diameter smaller than the widths of the slots 103 and 126 to avoid the need for precise vertical alignment of the components mounted on the door and the jamb of the door frame.

Yet another advantage of the locking devices 10, 82 and 100 is that they do not require the mounting of any components on the casing moulding 20. This is advantageous since, when such mouldings have curved outer surfaces, it is then often necessary, with many existing locking devices, to cut such a moulding to provide a flat surface on which a device component can be mounted.

A further advantage resulting from the attachment of the plate 44 or 116 on the edge surface 17 of the jamb 16 is that, in the event that an attempt is made to force open the door 12 by pushing on its outer face 14, the screws 45 are then subjected to a shearing action rather than to an axially directed force. As is well known, this provides greater strength.

Other modifications and variations in the specific structure hereinbefore described will be apparent to those conversant with the conventional structure of the devices of the subject type.

What is claimed is:

l. A locking device for use on a door having inner and outer faces and a free edge and hingedly mounted at an opposite edge in a door frame including a jamb having an edge surface opposite the free edge of the door when the door is in its fully closed position, which device is operative in a first locking position thereof to secure such a door in a fully closed position thereof, to allow partial opening of the door when said device is in a second locking position thereof and to allow the door to be opened completely when said device is in a released position thereof, and which device comprises:

a first mounting member adapted for attachment to the door;

a second mounting member adapted-for attachment to the jamb of the door frame;

a chain permanently secured to a first one of said first and second mounting members and releasably attached to a second one of said first and second mounting members and of such a length as to allow only partial opening of the door when said chain is attached to said second one of said first and second mounting members;

a locking member in the form of an arm hingedly mounted on said second mounting member for pivotal movement between a released first position in which said door can be opened from its fully closed position and a locking second position in which said arm effectively abuts the inner face of the door to prevent opening of the door from its fully closed position;

a holding memberoperatively associatedwith said locking member for releasably to maintain said arm of said locking member in said locking second position thereof.

2. A locking device as claimed in claim 1 in which said second mounting member is a mounting plate adapted for attachment to the edge surface of the jamb of a door frame so as to extend beyond the inner face of the door when that door is in its fully closed position.

3. A locking device as claimed in claim 2 in which one end of said chain is permanently connected to said mounting plate constituting said second mounting member. 7

4. A locking device as claimed in claim 1 in which said first mounting member comprises a door plate for attachment to the inner face of the door and having an elongated slot formed therein and in which slot a stud secured to a first end of said chain can be freely slidably disposed, and in which a second end of said chain is permanently secured to said second mounting member, said slot in said door plate being dimensioned at a first end thereof to allow removal of said stud from said slot only when the door is essentially in its fully closed position.

5. A locking device as claimed in claim 4 in which said arm is adapted to abut said door plate when said arm is in said second position thereof and in which said arm is adapted releasably to be engaged by said stud when said stud is moved toward a second end of said elongated slot in said door plate thereby to maintain said arm in said second position thereof, whereby said stud constitutes said holding member.

6. A locking device as claimed in claim 5 in which said arm is formed with a slot for removably receiving said stud when said stud is moved toward said second end of said elongated slot in said door plate.

7. A locking device as claimed in claim 6 which additionally comprises detent means for releasably retaining said stud within said slot in said arm.

8. A locking device as claimed in claim 7 in which said detent means comprises a chain-anchoring means secured to said second mounting member for releasable engagement with said chain between said first and second ends thereof thereby to prevent movement of said stud out of said slot in said arm.

9. A locking device as claimed in claim 8 in which said second mounting member is adapted for attachment to the edge surface of the jamb of a door frame so as to extend'beyond the inner face of the door when that door is in the fully closed position thereof.

10. A locking device as claimed in claim 9 in which said second mounting member and said arm comprise the two leaves of a hinge including a hinge sleeve and a hinge pin so that, when said locking device is mounted on a door in the manner specified, that hinge sleeve is disposed outwardlyof the inner face of the door. 1

11. A locking device as claimed in claim 10in which said chain-anchoring means comprises an upward extension of said hinge pin when said second mounting member is mounted on the jamb of a door frame in the manner specified.

12. A locking device, as claimed in claim 11 in which said second end of said chain is permanently secured to a downward extension of said hinge pin when said second mounting member is mounted on the jamb of a door frame in the manner specified.

13. A locking device as claimed in claim 10 in which said door plate is adapted to'be secured tothe inner face of the door with the elongated slot therein disposed generally horizontally and with said second end of said elongated slot disposed in general proximity to the free edge of the door and in which said slot in said arm extends generally horizontally into said arm from a free end thereof when said second mounting member is mounted on the jamb of the'door frame in the manner specified so that said slot in said arm and a terminal portion of said elongated slot in said door plate at said second end of said elongated slot are mutually aligned when said arm is pivoted in said second position thereof with said arm in abutment with said door plate.

14. Alocking device as claimed in claim 7 in which at least one of said elongated slot and said slot in said arm is formed with a relatively narrow neck portion, in which saidstud includes a shaft with front and rear portions separated by an axially facing and radially extending shoulder, said front and rear portions of said shaft having different diameters, one of which is greater than the width of said neck, and in which said stud includes a helical compression spring and a washer both disposed about the smaller one of said front and rear portions of said shaft of said stud, said spring being effective to urge said washer toward said shoulder, whereby said stud can be moved through said neck and into and out of said slot in said arm only by displacing said washer from said shoulder against the action of said spring, said neck and the stud structure thereby constituting said detent means.

15. A locking device as claimed in claim 6 in which said slot in said arm extends downwardly from a top edge of that arm when said second mounting member is mounted on the jamb of a door frame so that said slot in said arm and a terminal portion of said elongated slot in said door plate at said second end of said elongated slot are mutually aligned when said arm is pivoted into said second position thereof with said arm in abutment when said door plate.

16. A locking device as claimed in claim 15 in which said terminal portion of said elongated slot at said second end thereof and said slot in said arm have different widths thereby to provide alignment thereof for accommodation of said stud for different spacings between the free edge of the door and the edge surface of the jamb.

17. A locking device as claimed in claim 16 which additionally comprises detent means for releasably retaining said stud within said slot in said arm.

18. A locking device as claimed in claim 17 in which at least one of said elongated slot and said slot in said arm is formed with a relatively narrow neck portion, in which said stud includes a shaft with front and rear portions separated by an axially facing and radially extending shoulder, said front and rear portions of said shaft having different diameters, one of which is greater than the width of said neck, and in which said stud includes a helical compression spring and a'washer both disposed about the smaller one of said front and rear portions of said shaft of said stud, said spring being effective to urge said washer toward said shoulder, whereby said stud can be moved through said neck and into and out of said slot in said arm only by displacing said washer from said shoulder against the action of said spring, said neck and the stud structure thereby constituting said detent means.

19. A locking device as claimed in claim 17 in which said door plate is adapted to be secured to the inner face of the door with said elongated slot therein disposed generally vertically and with said second end of said elongated slot disposed at a lower end thereof.

20. A locking device as claimed in claim 19 in which said second mounting member is adapted for attachment to the edge surface of the jamb of a door frame so as to extend beyond the inner face of the door when that door is in the fully closed position thereof.

21. A locking device as claimed in claim 20 in which said second mounting member and said arm comprises the two arms of a hinge including a hinge sleeve and a hinge pin so that, when said locking device is mounted on a door in the manner specified, that hinge sleeve is disposed outwardly of the inner face of the door.

22. A locking device as claimed in claim 16 in which said door plate is adapted to be secured to the inner face of the door with the elongated slot therein disposed generally horizontally and with said second end of said elongated slot disposed in general proximity to the free edge of the door, and in which said terminal portion of said elongated slot is formed as a downward extension of said elongated slot near said second end thereof.

23. A locking device as claimed in claim 22 in which said second mounting member is adapted for attachment to the edge surface of the jamb of a door frame so as to extend beyond the inner face of the door when that door is in the fully closed position thereof.

24. A locking device as claimed in claim 23 in which said second mounting member and said arm comprise the two leaves of a hinge including a hinge sleeve and a hinge pin so that, when said locking device is mounted on a door in the manner specified, that hinge sleeve is disposed outwardly of the inner face of the door.

25. A locking device as claimed in claim 24 which additionally comprises detent means for releasably retaining said stud within said slot in said arm.

26. A locking device as claimed in claim 25 in which at least one of said elongated slot and said slot in said arm is formed with a relatively narrow neck portion, in which said stud includes a shaft with front and rear portions separated by an axially facing and radially extending shoulder, said front and rear portions of said shaft having different diameters, one of which is greater than the width of said neck, and in which said stud includes a helical compression spring and a washer both disposed about the smaller one of said front and rear portions of said shaft of said stud, said spring being effective to urge said washer toward said shoulder, whereby said stud can be moved through said neck and into and out of said slot in said arm only by displacing said washer from said shoulder against the action of said spring, said neck and the stud structure thereby constituting said detent means.

27. A locking device as claimed in claim 13 in which both said leaves of said hinge are formed with said slot therein for removably receiving said stud whereby a first leaf of said hinge constitutes said arm and a second leaf of said hinge constitutes said second mounting member for use on a door hinged at a left-hand vertical edge thereof and whereby said second leaf of said hinge constitutes said arm and said first leaf of said hinge constitutes said second mounting member for use on a door hinged at a right-hand vertical edge thereof.

28. A locking device as claimed in claim 27 in which said chain-anchoring means comprises an extension of said hinge pin at one end thereof and in which said second end of said chain is permanently secured to an extension of said hinge pin at the opposite end thereof. 

1. A locking device for use on a door having inner and outer faces and a free edge and hingedly mounted at an opposite edge in a door frame including a jamb having an edge surface opposite the free edge of the door when the door is in its fully closed position, which device is operative in a first locking position thereof to secure such a door in a fully closed position thereof, to allow partial opening of the door when said device is in a second locking position thereof and to allow the door to be opened completely when said device is in a released position thereof, and which device comprises: a first mounting member adapted for attachment to the door; a second mounting member adapted for attachment to the jamb of the door frame; a chain permanently secured to a first one of said first and second mounting members and releasably attached to a second one of said first and second mounting members and of such a length as to allow only partial opening of the door when said chain is attached to said second one of said first and second mounting members; a locking member in the form of an arm hingedly mounted on said second mounting member for pivotal movement between a released first position in which said door can be opened from its fully closed position and a locking second position in which said arm effectively abuts the inner face of the door to prevent opening of the door from its fully closed position; a holding member operatively associated with said locking member for releasably to maintain said arm of said locking member in said locking second position thereof.
 2. A locking device as claimed in claim 1 in which said second mounting member is a mounting plate adapted for attachment to the edge surface of the jamb of a door frame so as to extend beyond the inner face of the door when that door is in its fully closed position.
 3. A locking device as claimed in claim 2 in which one end of said chain is permanently connected to said mounting plate constituting said second mounting member.
 4. A locking device as claimed in claim 1 in which said first mounting member comprises a door plate for attachment to the inner face of the door and having an elongated slot formed therein and in which slot a stud secured to a first end of said chain can be freely slidably disposed, and in which a second end of said chain is permanently secured to said second mounting member, said slot in said door plate being dimensioned at a first end thereof to allow removal of said stud from said slot only when the door is essentially in its fully closed position.
 5. A locking device as claimed in claim 4 in which said arm is adapted to abut said door plate when said arm is in said second position thereof and in which said arm is adapted releasably to be engaged by said stud when said stud is moved toward a second end of said elongated slot in said door plate thereby to maintain said arm in said second position thereof, whereby said stud constitutes said holding member.
 6. A locking device as claimed in claim 5 in which said arm is formed with a slot for removably receiving said stud when said stud is moved toward said second end of said elongated slot in said door plate.
 7. A locking device as claimed in claim 6 which additionally comprises detent means for releasably retaining said stud within said slot in said arm.
 8. A locking device as claimed in claim 7 in which said detent means comprises a chain-anchoring means secured to said second mounting member for releasable engagement with said chain between said first and second ends thereof thereby to prevent movement of said stud out of said slot in said arm.
 9. A locking device as claimed in claiM 8 in which said second mounting member is adapted for attachment to the edge surface of the jamb of a door frame so as to extend beyond the inner face of the door when that door is in the fully closed position thereof.
 10. A locking device as claimed in claim 9 in which said second mounting member and said arm comprise the two leaves of a hinge including a hinge sleeve and a hinge pin so that, when said locking device is mounted on a door in the manner specified, that hinge sleeve is disposed outwardly of the inner face of the door.
 11. A locking device as claimed in claim 10 in which said chain-anchoring means comprises an upward extension of said hinge pin when said second mounting member is mounted on the jamb of a door frame in the manner specified.
 12. A locking device as claimed in claim 11 in which said second end of said chain is permanently secured to a downward extension of said hinge pin when said second mounting member is mounted on the jamb of a door frame in the manner specified.
 13. A locking device as claimed in claim 10 in which said door plate is adapted to be secured to the inner face of the door with the elongated slot therein disposed generally horizontally and with said second end of said elongated slot disposed in general proximity to the free edge of the door and in which said slot in said arm extends generally horizontally into said arm from a free end thereof when said second mounting member is mounted on the jamb of the door frame in the manner specified so that said slot in said arm and a terminal portion of said elongated slot in said door plate at said second end of said elongated slot are mutually aligned when said arm is pivoted in said second position thereof with said arm in abutment with said door plate.
 14. A locking device as claimed in claim 7 in which at least one of said elongated slot and said slot in said arm is formed with a relatively narrow neck portion, in which said stud includes a shaft with front and rear portions separated by an axially facing and radially extending shoulder, said front and rear portions of said shaft having different diameters, one of which is greater than the width of said neck, and in which said stud includes a helical compression spring and a washer both disposed about the smaller one of said front and rear portions of said shaft of said stud, said spring being effective to urge said washer toward said shoulder, whereby said stud can be moved through said neck and into and out of said slot in said arm only by displacing said washer from said shoulder against the action of said spring, said neck and the stud structure thereby constituting said detent means.
 15. A locking device as claimed in claim 6 in which said slot in said arm extends downwardly from a top edge of that arm when said second mounting member is mounted on the jamb of a door frame so that said slot in said arm and a terminal portion of said elongated slot in said door plate at said second end of said elongated slot are mutually aligned when said arm is pivoted into said second position thereof with said arm in abutment when said door plate.
 16. A locking device as claimed in claim 15 in which said terminal portion of said elongated slot at said second end thereof and said slot in said arm have different widths thereby to provide alignment thereof for accommodation of said stud for different spacings between the free edge of the door and the edge surface of the jamb.
 17. A locking device as claimed in claim 16 which additionally comprises detent means for releasably retaining said stud within said slot in said arm.
 18. A locking device as claimed in claim 17 in which at least one of said elongated slot and said slot in said arm is formed with a relatively narrow neck portion, in which said stud includes a shaft with front and rear portions separated by an axially facing and radially extending shoulder, said front and rear portions of said shaft having different diameters, one of which is greater than the width of said nEck, and in which said stud includes a helical compression spring and a washer both disposed about the smaller one of said front and rear portions of said shaft of said stud, said spring being effective to urge said washer toward said shoulder, whereby said stud can be moved through said neck and into and out of said slot in said arm only by displacing said washer from said shoulder against the action of said spring, said neck and the stud structure thereby constituting said detent means.
 19. A locking device as claimed in claim 17 in which said door plate is adapted to be secured to the inner face of the door with said elongated slot therein disposed generally vertically and with said second end of said elongated slot disposed at a lower end thereof.
 20. A locking device as claimed in claim 19 in which said second mounting member is adapted for attachment to the edge surface of the jamb of a door frame so as to extend beyond the inner face of the door when that door is in the fully closed position thereof.
 21. A locking device as claimed in claim 20 in which said second mounting member and said arm comprises the two arms of a hinge including a hinge sleeve and a hinge pin so that, when said locking device is mounted on a door in the manner specified, that hinge sleeve is disposed outwardly of the inner face of the door.
 22. A locking device as claimed in claim 16 in which said door plate is adapted to be secured to the inner face of the door with the elongated slot therein disposed generally horizontally and with said second end of said elongated slot disposed in general proximity to the free edge of the door, and in which said terminal portion of said elongated slot is formed as a downward extension of said elongated slot near said second end thereof.
 23. A locking device as claimed in claim 22 in which said second mounting member is adapted for attachment to the edge surface of the jamb of a door frame so as to extend beyond the inner face of the door when that door is in the fully closed position thereof.
 24. A locking device as claimed in claim 23 in which said second mounting member and said arm comprise the two leaves of a hinge including a hinge sleeve and a hinge pin so that, when said locking device is mounted on a door in the manner specified, that hinge sleeve is disposed outwardly of the inner face of the door.
 25. A locking device as claimed in claim 24 which additionally comprises detent means for releasably retaining said stud within said slot in said arm.
 26. A locking device as claimed in claim 25 in which at least one of said elongated slot and said slot in said arm is formed with a relatively narrow neck portion, in which said stud includes a shaft with front and rear portions separated by an axially facing and radially extending shoulder, said front and rear portions of said shaft having different diameters, one of which is greater than the width of said neck, and in which said stud includes a helical compression spring and a washer both disposed about the smaller one of said front and rear portions of said shaft of said stud, said spring being effective to urge said washer toward said shoulder, whereby said stud can be moved through said neck and into and out of said slot in said arm only by displacing said washer from said shoulder against the action of said spring, said neck and the stud structure thereby constituting said detent means.
 27. A locking device as claimed in claim 13 in which both said leaves of said hinge are formed with said slot therein for removably receiving said stud whereby a first leaf of said hinge constitutes said arm and a second leaf of said hinge constitutes said second mounting member for use on a door hinged at a left-hand vertical edge thereof and whereby said second leaf of said hinge constitutes said arm and said first leaf of said hinge constitutes said second mounting member for use on a door hinged at a right-hand vertical edge thereof.
 28. A locking device as claimed in claim 27 in which said chain-anchoring means comprises an extension of said hinge pin at one end thereof and in which said second end of said chain is permanently secured to an extension of said hinge pin at the opposite end thereof. 